JP2017141848A - Vehicle drive unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle drive unit which can efficiently supply lubricants accumulated in thinned portions of an internal wall face of a reduction gear casing to a rolling bearing.SOLUTION: In a vehicle drive unit which comprises an electric motor and a parallel-shaft gear reduction gear for decelerating the power of the electric motor, and transmitting it to drive wheels, and in which a gear shaft of the reduction gear is supported via a rolling bearing which is fit into bearing fitting holes 27a, 32a and 35a formed at the reduction gear casing 20, a plurality of bulkheads 20c are formed of thinned portions 20e formed at an internal wall face of the reduction gear casing 20, notches 20d are formed at the bearing fitting hole side of at least one bulkhead 20c out of the bulkheads 20c which are located at an upper side rather than the bearing fitting holes, and lubricants accumulated in the thinned portions 20e are discharged to the rolling bearing side from the notches 20d.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a vehicle drive device including an electric motor and a speed reducer that decelerates the power of the electric motor and transmits it to drive wheels.

  Patent Document 1 discloses a vehicle drive device that includes two electric motors and a speed reducer that independently drive left and right drive wheels.

  Since this type of vehicle drive device includes an electric motor for driving independently for each of the left and right drive wheels, a single motor drive device that drives the left and right drive wheels with a single common electric motor is provided. This has the advantage that a differential gear or the like that distributes the driving force of the two electric motors to the left and right is unnecessary.

  As shown in FIG. 10, a conventional vehicle drive device including two conventional electric motors and a speed reducer disclosed in Patent Document 1 and left and right electric motors 101L and 101R for individually driving left and right drive wheels and electric Reducers 102L and 102R that decelerate the rotation of the motors 101L and 101R are provided, and the reducers 102L and 102R are arranged at the center of the left and right electric motors 101L and 101R.

  As shown in FIG. 10, the reduction gears 102 </ b> L and 102 </ b> R are driven wheels via an input gear shaft 123 having an input gear to which power is transmitted from the motor shaft 112, and a drive shaft including a constant velocity joint 126 and an intermediate shaft 127. And an output gear shaft 125 that transmits a driving force to the input gear shaft 123, and the input gear shaft 123 and the output gear shaft 125 are arranged in parallel and offset from each other.

  One or more intermediate gear shafts 124 (counter shafts) are provided between the input gear shaft 123 and the output gear shaft 125 of the speed reducers 102L and 102R.

  The left and right speed reducers 102L and 102R are accommodated in parallel in a single speed reducer casing 128.

  A predetermined amount of lubricating oil is enclosed in the reduction gear casing 128 in order to lubricate the gear trains constituting the left and right reduction gears 102L, 102R. Then, the lubricating oil is splashed by the operation of the gears, and oil splashes generated at that time are supplied to the tooth surfaces of the gears of the reduction gear and the rolling bearings.

  It is desirable to efficiently supply the lubricating oil splashed by the gears to the gears and the rolling bearings. Further, the splashed lubricating oil is scattered on the inner wall surface of the reduction gear casing and flows down along the inner wall surface except for the oil that has flowed to the gears and the rolling bearing.

  By the way, the reduction gear casing is provided with a plurality of thinnings on the inner wall surface to reduce the weight, and the thickness is reduced, and a partition is provided between the thinnings to ensure rigidity.

Japanese Patent Laid-Open No. 11-243664

  The lubricating oil splashed on the inner wall surface of the reducer casing flows down along the wall surface. However, the lubricating oil accumulates in the thin wall of the inner wall surface, and the lubricating oil cannot be effectively used. .

  Accordingly, an object of the present invention is to provide a vehicle drive device that can efficiently supply the lubricating oil accumulated in the thin wall on the inner wall surface of the reduction gear casing to the rolling bearing.

  In order to solve the above-described problems, the present invention includes an electric motor and a speed reducer that decelerates the power of the electric motor and transmits the power to the drive wheels. The speed reducer is an input to which power is transmitted from the motor shaft. An input gear shaft having gears, an output gear shaft having an output gear for transmitting a driving force to the drive wheels, and one or more intermediate gear shafts having an intermediate gear provided between the input gear shaft and the output gear shaft; In the vehicle drive device in which the respective gear shafts are supported via rolling bearings fitted in bearing fitting holes provided in the casing. A plurality of partition walls are formed by a fillet provided on the inner wall surface of the casing, and a notch is provided on the bearing fitting hole side of at least one partition wall located above the bearing fitting hole. Meat meat The accumulated lubricating oil, characterized by discharging the rolling bearing side.

  In addition, a communication groove that communicates the space for housing the reduction gear and the internal space of the bearing fitting hole is provided, and lubricating oil discharged from a notch provided in the partition is supplied through the communication groove. It may be configured to do so.

  The notch and the communication groove may be provided at a position that does not intersect with a line of load acting on the rolling bearing by meshing of the gears.

  Moreover, it is good to provide the said notch in the said partition located above the said communication groove.

  Further, it is preferable that a lower portion of the meat fillet is formed in a tapered shape so that lubricating oil does not remain in the meat fillet on the inner wall surface of the speed reducer casing.

  As described above, according to the present invention, a plurality of partition walls are formed by the fillet provided on the inner wall surface of the reduction gear casing, and the bearing fitting holes of at least one partition wall located above the bearing fitting holes are provided. By providing a notch on the side and discharging the lubricating oil accumulated in the fillet from the notch to the rolling bearing side, the lubricating oil can be efficiently supplied to the rolling bearing.

1 is a cross-sectional plan view showing an embodiment of a vehicle drive device to which the present invention is applied. FIG. 2 is an enlarged cross-sectional plan view of the speed reducer portion of FIG. 1. 1 is a schematic plan view showing an example of an electric vehicle using a vehicle drive device according to the present invention. It is a top view of embodiment of FIG. It is explanatory drawing cut along the VV line of FIG. It is explanatory drawing which looked at the gear train of embodiment of FIG. 1 from the axial direction. It is explanatory drawing made into the cross section by the VII-VII line of FIG. FIG. 8 is an enlarged view of a region VIII portion surrounded by a broken line in FIG. FIG. 4 is an enlarged view of a region IV portion surrounded by a broken line in FIG. 1. It is a cross-sectional top view which shows the conventional 2 motor type vehicle drive device.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
The two-motor type vehicle drive device A shown in FIG. 1 has a reduction gear casing 20 that houses two reduction gears 2L and 2R in parallel in the left and right directions, and two electric motors 1L on the left and right sides of the reduction gear casing 20. 1R motor casings 3L and 3R are fixedly arranged.

  An electric vehicle C shown in FIG. 3 is a front-wheel drive system, and is a two-motor vehicle drive device that independently drives a chassis 51, front wheels 52 as drive wheels, rear wheels 53, and left and right drive wheels. A two-motor type vehicle drive device A is mounted on a chassis 51 at the center of left and right front wheels 52 as drive wheels, and the driving force of the two-motor type vehicle drive device A is a constant velocity joint. 15 and the intermediate shaft 16 are transmitted to the front wheels 52 which are left and right drive wheels.

  As a mounting form of the two-motor type vehicle driving device A, a rear wheel driving method and a four wheel driving method may be used in addition to the front wheel driving method shown in FIG.

  The left and right electric motors 1L, 1R in the two-motor type vehicle drive device A are housed in motor casings 3L, 3R, as shown in FIG.

  The motor casings 3L and 3R include cylindrical motor casing bodies 3aL and 3aR, outer walls 3bL and 3bR that close the outer surfaces of the motor casing bodies 3aL and 3aR, and reduction gears on the inner surfaces of the motor casing bodies 3aL and 3aR. It consists of inner walls 3cL and 3cR separated from 2L and 2R. The inner walls 3cL and 3cR of the motor casing bodies 3aL and 3aR are provided with openings for drawing out the motor shaft 12a.

  As shown in FIG. 1, the electric motors 1 </ b> L and 1 </ b> R are of a radial gap type in which a stator 11 is provided on the inner peripheral surface of the motor casing body 3 aL and 3 aR, and a rotor 12 is provided on the inner periphery of the stator 11. I am using something. The electric motors 1L and 1R may be axial gap types.

  The rotor 12 has a motor shaft 12a in the center, and the motor shaft 12a is drawn from the openings of the inner side walls 3cL and 3cR of the motor casing bodies 3aL and 3aR to the speed reducers 2L and 2R, respectively. A seal member 13 is provided between the openings of the motor casing bodies 3aL and 3aR and the motor shaft 12a.

  The motor shaft 12a is rotatably supported by the rolling bearings 14a and 14b on the inner side walls 3cL and 3cR and the outer side walls 3bL and 3bR of the motor casing bodies 3aL and 3aR (FIG. 1).

  As shown in FIGS. 1 and 4, the speed reducer casing 20 that accommodates the two speed reducers 2 </ b> L and 2 </ b> R provided in parallel on the left and right is a central casing 20 a and left and right fixed to both side surfaces of the central casing 20 a. It has a three-piece structure of side casings 20bL and 20bR. The left and right side casings 20bL and 20bR are fixed to the openings on both sides of the central casing 20a by a plurality of bolts 26L and 26R.

  The side surfaces of the side casings 20bL and 20bR of the reduction gear casing 20 on the outboard side (outside of the vehicle body) and the motor casing bodies 3aL and 3aR of the electric motors 1L and 1R are fixed to the inner side walls 3cL and 3cR by a plurality of bolts 29. Thus, the two electric motors 1L and 1R are fixedly arranged on the left and right sides of the reduction gear casing 20 (FIGS. 1 and 4).

  As shown in FIG. 1, a partition wall 21 is provided at the center of the center casing 20a. The reduction gear casing 20 is divided into two left and right by the partition wall 21, and independent left and right accommodation chambers for accommodating the two reduction gears 2L and 2R are provided in parallel.

  As shown in FIG. 1, the speed reducers 2L and 2R are provided symmetrically and have large input gear shafts 23L and 23R each having an input gear 23a to which power is transmitted from the motor shaft 12a, and the input gear 23a. The intermediate gear shafts 24L and 24R having small diameter gears 24b meshing with the diameter gear 24a and the output gear 25a, and the output gear 25a are pulled out from the speed reducer casing 20, and the constant velocity joint 15 and the intermediate shaft 16 (FIG. 3) are connected. It is a parallel shaft gear reducer provided with the output gear shafts 25L and 25R that transmit the driving force to the drive wheels via the shafts. The input gear shafts 23L and 23R, the intermediate gear shafts 24L and 24R, and the output gear shafts 25L and 25R of the two left and right speed reducers 2L and 2R are coaxially arranged.

  Both ends of the input gear shafts 23L, 23R of the speed reducers 2L, 2R roll into bearing fitting holes 27a formed on both the left and right sides of the partition wall 21 of the central casing 20a and bearing fitting holes 27b formed in the side casings 20bL, 20bR. The bearings 28a and 28b are rotatably supported. The bottoms of the bearing fitting holes 27a and 27b are stepped and are formed with a thinner thickness on the inner peripheral side than the wall part with which the outer rings of the rolling bearings 28a and 28b abut.

  The end portions on the outboard side of the input gear shafts 23L and 23R are drawn outward from the opening portions 27c provided in the side casings 20bL and 20bR, and the openings 27c and the outer end portions of the input gear shafts 23L and 23R are connected to each other. An oil seal 31 is provided between them to prevent leakage of lubricating oil sealed in the speed reducers 2L and 2R and intrusion of muddy water from the outside.

  The motor shaft 12a has a hollow structure, and the input gear shafts 23L and 23R are inserted into the hollow motor shaft 12a. The input gear shafts 23L and 23R and the motor shaft 12a are coupled to each other by a spline (including the serrations).

  The intermediate gear shafts 24L and 24R are stepped gear shafts having a large-diameter gear 24a meshing with the input gear 23a and a small-diameter gear 24b meshing with the output gear 25a on the outer peripheral surface. At both ends of the intermediate gear shafts 24L and 24R, rolling bearings 34a and 34b are formed into bearing fitting holes 32a formed on both surfaces of the partition wall 21 of the central casing 20a and bearing fitting holes 32b formed on the side casings 20bL and 20bR. Is supported through. And the bottom part of the bearing fitting holes 32a and 32b is formed in a stepped shape with a thinner thickness on the inner peripheral side than the wall part with which the outer ring of the rolling bearings 34a and 34b abuts.

  The output gear shafts 25L and 25R have a large-diameter output gear 25a, and are formed in bearing fitting holes 35a formed on both surfaces of the partition wall 21 of the central casing 20a and bearing fitting holes 35b formed on the side casings 20bL and 20bR. It is supported by rolling bearings 37a and 37b. And the bottom part of the bearing fitting holes 35a and 35b is formed in a stepped shape in which the inner peripheral side is thinner than the wall part with which the outer ring of the rolling bearings 37a and 37b abuts.

  Outboard side ends of the output gear shafts 25L and 25R are pulled out to the outside of the reduction gear casing 20 through openings 35c formed in the side casings 20bL and 20bR, and the output gear shafts 25L and 25R are pulled out to the outboard side. The outer joint portion 15a of the constant velocity joint 15 is splined to the outer peripheral surface of the end portion.

  The constant velocity joint 15 coupled to the output gear shafts 25L and 25R is connected to the drive wheel 52 via the intermediate shaft 16 (FIG. 3).

  An oil seal 39 is provided between the end of the output gear shafts 25L and 25R on the outboard side and the opening 35c formed in the side casings 20bL and 20bR, and leakage of the lubricating oil sealed in the speed reducers 2L and 2R It also prevents the entry of muddy water from the outside.

  Although FIG. 9 shows the intermediate gear shaft 24L, rolling bearings 28a and 28b are provided at both ends of the input gear shafts 23L and 23R, the intermediate gear shaft 24R, and the output gear shafts 25L and 25R, including the intermediate gear shaft 24L. , 34a, 34b, 37a, 37b are fitted, and the outer ring 41 of the rolling bearings 28a, 28b, 34a, 34b, 37a, 37b is fitted to the bearing fitting holes 27a, 32a, 35a of the central casing 20a and the side surfaces. It is fitted in the bearing fitting holes 27b, 32b, 35b of the casings 20bL, 20bR.

  The inner rings 40 of the rolling bearings 28a, 28b, 34a, 34b, 37a, 37b and the gear shafts 23L, 23R, 24L, 24R, 25L, 25R are fitted with tightness so that they can be rotated at the center of rotation (tight). The outer ring 41 of the rolling bearings 28a, 28b, 34a, 34b, 37a, and 37b and the bearing fitting holes 27a, 32a, 35a27b, 32b, and 35b can be easily assembled into each gear shaft. Are fitted with a gap (loose fitting). There is a gap of several tens of μm between the bearing fitting holes 27a, 32a, 35a, 27b, 32b, and 35b and the outer ring 41 of the rolling bearing.

  In the case of fitting with such a gap, it is necessary to supply sufficient lubricating oil to the gap in order to prevent wear of the bearing fitting holes 27a, 32a, 35a, 27b, 32b, and 35b. Therefore, in this embodiment, the lubricating oil is positively supplied between the bearing fitting holes 27a, 32a, 35a, 27b, 32b, and 35b and the outer ring 41 of the rolling bearing.

  In the oil bath method, the lubricating oil staying in the lower portion of the speed reducer casing 20 is splashed by the gears, and the oil droplets generated at that time are supplied to the tooth surface and the rolling bearing. In order to supply the lubricating oil into the bearing, it is effective to generate an oil flow penetrating in the axial direction inside the bearing.

  Therefore, in this embodiment, a structure for generating this flow is adopted. As shown in FIG. 9 in which the portion surrounded by the broken line IV in FIG. 1 is enlarged, the space G1 in the casing 20 housing the speed reducer and the bearing are formed on the inner peripheral surface of the bearing fitting hole 32b into which the rolling bearing 34b is fitted. At least one groove 45 communicating with the internal space G2 of the fitting hole 32b is provided. That is, as shown in FIG. 9, a space closed by a gear space G1 of the casing 20 where gears and the like exist with the rolling bearing 34b as a boundary and a bearing fitting hole 32b provided in the side casing 20bL of the casing 20 is defined as an internal space. Assuming G2, one or more communication grooves 45 for communicating the gear space G1 and the internal space G2 are provided on the inner peripheral surface of the bearing fitting hole 32b provided in the side casing 20bL to which the outer ring 41 of the rolling bearing 34b is fitted. Yes.

  By this communication groove 45, the oil flowing in from the communication groove 45 flows through the internal space G2 and is discharged through the internal space of the rolling bearing 34b, or the oil flowing in from the rolling bearing 34b passes through the internal space G2. A flow discharged through the communication groove 45 is generated. The lubricating oil flowing in from the communication groove 45 is positively supplied between the bearing fitting hole 32b and the outer ring 41 of the rolling bearing 34b.

  In order to simplify the description, the inner ring 40, the outer ring 41, the rolling element 42, and the communication groove 45, which are components of the rolling bearings 28a, 28b, 34a, 34b, 37a, 37b, have the same reference numerals.

  As described above, the speed reducer casing 20 is provided with a plurality of thinnings 20e to reduce the weight to reduce the weight, and a partition 20c is provided between the thinnings 20e to ensure rigidity. ing. FIG. 5 shows the central casing 20a, but the side casings 2bL and 2bR are similarly provided with a meat fillet 20e and a partition wall 20c. The lubricating oil scattered on the inner wall surface of the speed reducer casing 20 flows down along the inner wall surface, but the lubricating oil accumulates in the meat thinning 20e on the inner wall surface.

  Therefore, in this embodiment, a notch 20d for supplying the lubricating oil remaining in the fillet 20e to the rolling bearings 28a, 34a, and 37a is formed in the partition wall 20c located above the bearing fitting holes 35a, 32a, and 27a. The lubricating oil discharged from the notch 20d is guided to the communication groove 45, and the lubricating oil is supplied from the communication groove 45 to the rolling bearings 28a, 34a, 37a.

  Lubricating oil collected in the upper three fillets 20e is supplied to the bearing fitting holes 27a through the notches 20d. That is, the lubricating oil collected in 20e1 in the figure is sent from the notch 20d to the adjacent meat fillet 20e2, and is sent from the cutout 20d to the adjacent meat thinning 20e3 together with the lubricating oil collected in the meat fillet 20e. The notch 20d provided in the meat fillet 20e is connected to the communication groove 45, and the lubricating oil accumulated in the three meat fillets 20e1, 20e2, 20e3 from the notch 20d is supplied from the communication groove 45 to the rolling bearing 28a. The

  Lubricating oil collected in the upper four meat thinnings 20e is supplied to the bearing fitting holes 32a through the notches 20d. In other words, the lubricating oil accumulated in 20e4 in the figure is sent from the notch 20d to the adjacent meat fillet 20e6, and the lubricating oil accumulated in the meat fillet 20e5 is sent from the cutout 20d to the lower meat fillet 20e6. The lubricating oil sent from the meat fillet 20e4 and the meat fillet 20e5 is sent from the cutout 20d to the adjacent meat fillet 20e7 together with the lubricant accumulated in the meat fillet 20e6. The notch 20d provided in the meat fillet 20e7 is connected to the communication groove 45, and the lubricating oil accumulated in the four meat fillets 20e4, 20e5, 20e6, and 20e7 from the notch 20d is supplied from the communication groove 45 to the rolling bearing 34a. The

  Lubricating oil collected in the upper three fillets 20e is supplied to the bearing fitting holes 35a through the notches 20d. That is, the lubricating oil collected in 20e8 in the figure is sent from the notch 20d to the adjacent meat fillet 20e9, and is sent from the cutout 20d to the adjacent meat thinning 20e10 together with the lubricating oil collected in the meat fillet 20e. The cutout 20d provided in the meat fillet 20e10 is connected to the communication groove 45, and the lubricating oil accumulated in the three fillets 20e8, 20e9, and 20e10 from the cutout 20d is supplied from the communication groove 45 to the rolling bearing 37a. The

  In this way, the lubricating oil accumulated in the fillet 20e can be flowed to the rolling bearing side, and the lubricating oil can be efficiently supplied to the gears and the rolling bearing by oil bath circulation.

  Since the lubricating oil is supplied from the communication groove 45, the notch 20 d is provided in the partition wall 20 c above the communication groove 45. And since the partition 20c is provided in order to ensure rigidity, it is preferable to provide in the position which avoided the stress load area | region on the acting line of the load which acts on the bearing mentioned later.

  As shown in FIG. 7, the lower portion of the fillet 20e is formed in a tapered shape so that the accumulated lubricating oil can easily flow out. The taper angle α may be about 5 to 10 degrees. Normally, in the cast product, the draft angle is about 1.5 degrees, but the taper angle α is larger than that to improve the flow of the lubricating oil. Since the taper of the lower part of the meat fillet 20 is not less than the draft required for the casing, there is no concern about cost increase.

  The size of the notch depth M and the length N of the notch 20d shown in the enlarged view of FIG. 8 will be described. Lubricating oil can be discharged more efficiently if the cut depth M of the notch 20d is 3 mm or more and is made as large as possible within the range that maintains the strength of the partition wall 20c. Similarly, the lubricating oil can be discharged more efficiently when the length N of the notch 20d is 3 mm or more and is made as large as possible within the range that maintains the strength of the partition wall 20c.

  5, for the sake of convenience, the bearing fitting holes 27a, 32a, and 35a of the central casing 20a have been described. Similarly, the bearing fitting holes 27b, 32b, and 35b of the side casings 20bL and 20bR are similarly provided with the respective bearing fitting holes. One or more communication grooves 45 that allow the gear space G1 and the internal space G2 to communicate with each other are provided on the inner peripheral surface. The partition wall 20c is provided with a notch 20d, and the lubricating oil discharged from the notch 20d is guided to the communication groove 45, and the lubricating oil is supplied from the communication groove 45 to the rolling bearings 28b, 34b, and 37b.

  By the way, when the communication groove 45 is provided on the inner peripheral surface of the bearing fitting hole of the casing 20, that is, the surface on which the outer ring of the rolling bearing is fitted, when the rolling element 42 passes the phase of the communication groove 45, The outer ring 41 may be deformed by a load acting on the outer ring 41 via the rolling element 42. Along with the deformation of the outer ring 41, the roundness of the outer ring raceway surface may deteriorate and adversely affect vibration / sound and durability. This load is also applied as a stress load to the partition wall 20c.

  The input gear shaft 23L and the intermediate gear shaft of the speed reducer 2L when the inboard side (inside the vehicle body) is viewed from the outboard side in the two-motor type vehicle drive device A mounted on the electric vehicle C shown in FIG. FIG. 6 shows the arrangement of the gears 24L and 25L. The input gear shaft 23L is positioned in front of the vehicle from the output gear shaft 25L, and the intermediate gear shaft 24L is positioned below the input gear shaft 23L and the output gear shaft 25L. Here, the speed reducer 2R is in a relation in which FIG. 6 is mirror-symmetrical. As shown in FIG. 6, when the gears are in meshing rotation, a load zone in which a load acts between the rolling elements and the raceway is present in the rolling bearing over a certain circumferential range. The load is the largest on the load action line. FIG. 6 shows in which direction the load action line is generated. Similarly, FIG. 5 shows in which direction the load action line is generated.

  Therefore, in this embodiment, the communication groove 45 is provided on the inner peripheral surface of the bearing fitting hole of the reduction gear casing 20 so that the line of action of the load acting on the rolling bearing does not intersect the communication groove 45. Similarly, the notch 20d formed in the partition wall 20c is also provided at a position that does not intersect the line of action of the load acting on the rolling bearing.

  Next, the action line of the load will be described with reference to the gear arrangement in FIG. In this embodiment, the load action line is defined below.

  Here, a gear meshing row formed by the input gear 23a and the large-diameter gear 24a is designated as A row, and a gear meshing row constituted by the small-diameter gear 24b and the output gear 25a is designated as the B row. The axis of the input gear shaft 23L is x, the axis of the intermediate gear shaft 24L is y, and the axis of the output gear shaft 25L is z.

  In FIG. 6, L1A and L2A are perpendicular to the straight line connecting the axial center x and the axial center y, and are straight lines passing through the axial center x and the axial center y, respectively. L2B and L3B are perpendicular to the straight line connecting the axis y and the axis z, and are straight lines passing through the axis y and the axis z, respectively.

  L1D is an action line of a load acting on the rolling bearings 28a and 28b of the input gear shaft 23L during acceleration (drive side) due to the meshing of the input gear 23a and the large-diameter gear 24a, that is, the meshing of the gear train A. .

  By engaging the gear train A with the input gear 23a and the large-diameter gear 24a, the line of load acting on the rolling bearings 28a and 28b of the input gear shaft 23L during deceleration (coast side) is L1C.

  By engaging the gear train A with the input gear 23a and the large-diameter gear 24a, the acting line of the load acting on the rolling bearings 34a and 34b of the intermediate gear shaft 24L during acceleration (drive side) is L2DA.

  By engaging the gear train A with the input gear 23a and the large-diameter gear 24a, the acting line of the load acting on the rolling bearings 34a and 34b of the intermediate gear shaft 24L during deceleration (coast side) is L2CA.

  The gear engagement of the gear train B by the small-diameter gear 24b and the output gear 25a, that is, the engagement of the gear train B, the line of load acting on the rolling bearing 34a of the intermediate gear shaft 24L during acceleration (drive side) is denoted by L2DB. To do.

  By engaging the gear train B with the small-diameter gear 24b and the output gear 25a, an action line of a load acting on the rolling bearings 34a and 34b of the intermediate gear shaft 24L at the time of deceleration (coast side) is L2CB.

  The line of load acting on the rolling bearings 37a and 37b of the output gear shaft 25L during acceleration (drive side) due to the meshing of the gear train B of the small diameter gear 24b and the output gear 25a is L3D.

  By engaging the gear train B with the small-diameter gear 24b and the output gear 25a, a line of load acting on the rolling bearings 37a and 37b of the output gear shaft 25L during deceleration (coast side) is L3C.

An angle φ is formed between L1D and L1A and between L1C and L1A.
An angle φ is formed between L2DA and L2A and between L2CA and L2A.
An angle φ ′ is formed between L2DB and L2B and between L2CB and L2B.
An angle φ ′ is formed between L3D and L3B and between L3C and L3B.

The angles φ and φ ′ are given by the following equations based on the tooth surface pressure angle and the tooth surface twist angle of the gear.
tanφ = tan α / cos β
tan φ ′ = tan α ′ / cos β ′
Here, α and α ′ are tooth surface pressure angles, and β and β ′ are tooth surface torsion angles.

  That is, the line of action of the load can be defined by the axial center position and the gear specifications (pressure angle and torsion angle). In the present invention, at least one communication groove 45 is formed at a position not intersecting with the load acting line obtained by the shaft center position and the gear specifications (pressure angle and torsion angle), and the gear space G1 and the internal space G2 are communicated. I am letting. Further, the notch 20d provided in the partition wall 20c is also provided at a position that does not intersect the load acting line obtained by the axial center position and the gear specifications (pressure angle and torsion angle).

  The present invention is not limited to the above-described embodiments, and can of course be implemented in various forms without departing from the gist of the present invention. The scope of the present invention is claimed. The equivalent meanings recited in the claims, and all modifications within the scope.

1L, 1R: Electric motor 2L, 2R: Reducer 3L, 3R: Motor casing 3aL, 3aR: Motor casing body 3bL, 3bR: Outer wall 3cL, 3cR: Inner wall 11: Stator 12: Rotor 12a: Motor shaft 13: Seal Member 14a, 14b: Rolling bearing 15: Constant velocity joint 15a: Outer joint part 16: Intermediate shaft 20: Reduction gear casing 20a: Central casing 20c: Partition 20d: Notch 20e: Meat fillet 20bL, 20bR: Side casing 21: Partition Wall 23L, 23R: Input gear shaft 23a: Input gear 24L, 24R: Intermediate gear shaft 24a: Large diameter gear 24b: Small diameter gear 25L, 25R: Output gear shaft 25a: Output gear 26L, 26R: Bolts 27a, 27b, 32a, 32b, 35a, 35b: Bearing fitting holes 7c: opening 28a, 28b, 34a, 34b, 37a, 37b: rolling bearing 29: bolt 31: oil seal 35c: opening 39: oil seal 40: inner ring 41: outer ring 42: rolling element 42C: axial center line 45 : Communication groove 46: Circumferential structure 51: Chassis 52: Front wheel 53: Rear wheel A: Vehicle drive device C with reduction gear for automobile C: Electric vehicle G1: Gear space G2: Internal space α, α ': Tooth surface pressure angle β , Β ′: tooth surface twist angle φ, φ ′: angles x, y, z: shaft centers L1D, L1C, L2DA, L2CA, L2DB, L2CB, L3D, L3C: load action line

Claims (6)

An electric motor and a speed reducer that decelerates the power of the electric motor and transmits the power to the drive wheel. The speed reducer includes an input gear shaft having an input gear to which power is transmitted from the motor shaft, and a driving force applied to the drive wheel. An output gear shaft having an output gear for transmitting the power and one or more intermediate gear shafts having an intermediate gear provided between the input gear shaft and the output gear shaft are arranged in parallel and accommodated in the speed reducer casing. In the vehicle drive device in which each gear shaft is supported via a rolling bearing fitted in a bearing fitting hole provided in the casing,
A plurality of partition walls are formed by a fillet provided on the inner wall surface of the reduction gear casing, and a notch is provided on the bearing fitting hole side of at least one partition wall located above the bearing fitting hole. Lubricating oil accumulated in the meat fillet from the notch is discharged to the rolling bearing side.   A communication groove that communicates the space for housing the speed reducer and the internal space of the bearing fitting hole is provided, and lubricating oil discharged from a notch provided in the partition is supplied through the communication groove. The vehicle drive device according to claim 1.   2. The vehicle drive device according to claim 1, wherein the notch is provided at a position that does not intersect with an action line of a load acting on the rolling bearing by meshing of a gear.   The vehicle drive device according to claim 2, wherein the communication groove is provided at a position that does not intersect with an action line of a load acting on the rolling bearing by meshing of a gear.   The vehicle drive device according to any one of claims 2 to 4, wherein the notch is provided in the partition located above the communication groove.   3. The vehicle drive device according to claim 1, wherein a lower portion of the meat filling is formed in a tapered shape so that lubricating oil does not remain in the meat filling of the inner wall surface of the speed reducer casing.

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